I was going to write my own review, but I found the following review on Amazon. I added my own comments in red text.

Amazon review:

This is a 4-DVD follow along type kettlebell workout. Actually, there are ten different workouts instead of 15 as it claims on the title. Granted, by combining the workouts, you can get dozens of combinations but still there are ten individual workouts in the box.

DVD's 1 and 2

The first two DVDs are about 30 minutes in length and both include warm up and a strength/size workout, DVD 1 is for upper body and DVD 2 for lower body. (This is a plus. I did not expect the DVD to have an upper/lower body split; I just assumed it would be all full body workouts).

Equipment Needed

You need two relatively heavy kettlebells of the same size, and a bench, stool or plyometric boxes for the workouts. The workouts consist of 7 or 8 different exercises, each done for 5 or 10 reps each set. All sets are done in back to back fashion, with 1-3 minutes of rest between the circuits. You are supposed to do three circuits in a workout, taking some 30 minutes.

DVD's 3 and 4

Disc 3 includes three different 10-minute abs/core workouts and two circuit workouts taking 20-25 minutes each. You'll need one relatively light kettlebell for these exercises.

Disc 4 includes a kettlebell circuit workout of some 25 minutes and two cardio workouts, one of ten minutes and the other taking 20 minutes. You'll need one relatively light kettlebell for these workouts.

The production of the film of OK, but there is nothing fancy either. There is no time counter in the exercises you do for time (like the cardio workouts), or rep counter for the exercises you'll do for reps. (You don't need a time counter, you just need to follow Steve because you can see he is watching the time).

The workouts have not been divided into chapters, so if you want to skip an exercise, you have to use the fast forward button instead of just skipping to next chapter by a simple push of a button.

Kettlebell Circuit Workouts

On circuit workouts you'll do the same number of reps on each exercise, irrespective of the relative toughness of the individual exercise. So you'll do ten reps of swings, and ten reps of Turkish get-ups, although the latter is much harder exercise. In my opinion, it would have been better if the rep ranges would reflect the relative toughness of the exercises. (I agree)

Kettlebell Exercise Instructions

There is hardly any instruction on the exercises; therefore this DVD is not for beginners as you are supposed to know the exercises beforehand. (TheComplete Guide to Kettlebell Liftinggives excellent instructions) In my opinion, the workouts are not extreme either, so this workout suits for everyone who has already mastered the moves. The exercises are not technically difficult (windmill being probably the most challenging move technically), so you should not be scared by the word "extreme" in the title. You can easily make the workout harder or easier by selecting a suitable weight.

Conclusion

This is far from perfect workout DVD, but for the money you'll get almost four hours of different kinds of workouts ranging from 10 minutes up, emphasizing cardiovascular endurance or size/strength, depending on your choice. However I find it pity they have not put that little extra on the final touches to make this a 5-star product.